Greetings. I'm not sure this is the right section to post this, but if not correct, I would ask that the mods relocate.

A well-known breeder claims that he has, "bred all predatory fry eating, out of his female guppies, through a few generations of selective breeding."

I'm no scientist, but from what I remember from my introduction to evolutionary biology, what has taken hundreds of thousands of years, at a minimum, to be genetically coded as a survival mechanism (big fish eat little fish), could hardly be wiped clean in a year of selective breeding at most.

Is this claim as erroneous as I interpret it to be or do I need to audit a few courses in my old age? lol.

I appreciate the fact that this does not rise to the level of most questions, here, but in our little world of livebearing tropical fish enthusiasts, a claim like this can set a breeding program back by years.

the time doesn't matter. If you were breeding elephants, even 20 years wouldn't be enough, but with mice 1 year could do it The important thing is number of generations Thus if he had some fishes, which breed in 2 months, he could have about 5 generations in 1 year and that could be enough for some change.However, question is, whether his trait can be selected like that.